OnlineSubsystemNull sessions don't work on server with multiple network interfaces

I am using the null online subsystem to set up LAN multiplayer sessions in my game.
It works as long as I only have the “Ethernet adapter Ethernet” network interface on my (Windows 10) computer.
As soon as I add another network interface, such as when installing VirtualBox, the multiplayer sessions stop working.

Should I tell the session system to use a specific network interface somehow? How do I do that?

In case someone has the same problem in the future.

The issue seems to be that the LAN session code is using the first interface it finds.
So if there are multiple, chances are it will pick the wrong one.

Starting the game with the commandline argument “-MULTIHOME={the ip address of the interface you want to use}” will make it work.

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Is there anyway to do it in editor without the commandline argument?

It seems like you can add commandline parameters in editor preferences under playplay in standalone game → * additional launch parameters*.

I haven’t tested that though.